All model output in the CMIP5 archive is available for “non-commercial research and educational purposes.” A subset (about three-quarters of the models) of the data has also been released for “unrestricted” use, see table in the document "Modeling Groups and their Terms of Use" (Word doc) . Users registering to access CMIP5 output will be granted access to some or all of the data, depending on which of the following terms of use are agreed to:

Terms of use for data limited to non-commercial research and educational purposes

a) I agree to restrict my use of CMIP5 model output for non-commercial research and educational purposes only.

Results from non-commercial research are expected to be made
generally available through open publication and must not be
considered proprietary. Materials prepared for educational purposes
cannot be sold. These restrictions may only be relaxed by permission
of the individual modeling groups responsible for the simulations.

OR

Terms of use for unrestricted data:

a) I understand that the subset of CMIP5 model output that will be made accessible to this group has been designated for "unrestricted" use.

For both groups of users, the terms of use include these additional statements:

b) I will hold no individual(s), organization(s), or group(s) responsible for any errors in the models or in their output data.

c) In publications that rely on the CMIP5 model output, I will appropriately credit the data providers by an acknowledgment similar to the following:

“We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modeling groups (listed in Table XX of this paper) for producing and making available their model output. For CMIP the U.S. Department of Energy's Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals.”

where “Table XX” in your paper should list the models and modeling groups that provided the data you used.

d) I understand that Digital Object Identifiers (DOI’s used, for example, in journal citations) will be assigned to various subsets of the CMIP5 multi-model dataset, and when available and as appropriate, I will cite these references in my publications. I will consult the CMIP5 website (http://cmip-pcmdi.llnl.gov/cmip5/) to learn how to do this.

e) I acknowledge the potential limitations of the data obtained from this archive. These may include (but are not necessarily limited to) errors in the models, shortcomings in the experiment designs, the conjectural quality of the forcing scenarios used to drive the models, and so on.

f) I understand that although the model output has been subjected to a quality control procedure, unrecognized errors almost certainly remain.

g) To aid participating groups in understanding and improving upon their models’ behaviors, I will respond to reasonable requests from the WGCM for feedback about my CMIP5 research results (e.g., reporting model deficiencies, recording CMIP5 publications, etc.).

h) Although I may freely share downloaded CMIP5 data with close collaborators, I understand that I may not redistribute the data more widely without abiding by additional terms of use enumerated below.

Users may share data with close collaborators who have agreed to abide by the above terms of use. A research institution wishing to share CMIP5 data *internally* among its staff may seek permission to do so from PCMDI by submitting to PCMDI this form permission_to_share_form.docx. Others planning to redistribute CMIP5 model output must abide by additional "terms of use" enumerated below.

*Additional* terms of use for redistribution of CMIP5 model output:

For the following reasons, users are discouraged from downloading CMIP5 data for the purpose of redistributing it to others (beyond their close collaborators):

The CMIP5 data archive is a dynamic collection of files, and it will be difficult to keep a copy (of even a small subset of the archived data) up to date. (Even if an automated update procedure is implemented, the resources allocated to the official CMIP5 archive could be unduly affected.)

The modeling groups have requested that users downloading CMIP5 data be registered and agree to the terms of use, and PCMDI alone is responsible for this.

If despite the above arguments against it, you wish to redistribute CMIP5 data to others, there are specific conditions that must be met. In addition to abiding by the terms of use (see above), anyone redistributing CMIP5 output (beyond their close collaborators) is required to:

Record contact information for all users downloading CMIP5 output. These records must be sent to PCMDI quarterly in a format acceptable to PCMDI. These records will be used 1) to inform users when flaws in model output are discovered, and 2) to gauge the impact of CMIP5 results through the collection of usage statistics, as requested by the modeling groups.

Continually update data holdings to accurately reflect the CMIP5 archive. This will prevent known flawed data from being distributed.

Display a warning that the modeling groups have not checked or approved of the data being distributed.

In general, the operation of ESGF and its performance in serving other users must not be adversely affected.

Note that commercial use of all but "unrestricted" data is strictly forbidden. In particular, paid advertisements must not appear on websites providing access to data (or derived data products) from CMIP5 models that have been designated as being available only for "non-commercial research and educational purposes".